U.S. patent application number 14/615739 was filed with the patent office on 2015-09-10 for light source device, lighting device, and luminaire.
The applicant listed for this patent is Panasonic Intellectual Property Management Co., Ltd.. Invention is credited to Junichi HASEGAWA, Akinori HIRAMATU, Shigeru IDO, Hiroshi KIDO, Daisuke UEDA.
Application Number | 20150257212 14/615739 |
Document ID | / |
Family ID | 53884091 |
Filed Date | 2015-09-10 |
United States Patent
Application |
20150257212 |
Kind Code |
A1 |
IDO; Shigeru ; et
al. |
September 10, 2015 |
LIGHT SOURCE DEVICE, LIGHTING DEVICE, AND LUMINAIRE
Abstract
A control unit of a light source device after activation time is
configured to turn on switches respectively connected in series
with light sources, in prescribed order. The light source device
and a lighting device are configured to transmit characteristics of
the light sources, based on a voltage change depending on a pattern
of on and off of the switches.
Inventors: |
IDO; Shigeru; (Osaka,
JP) ; KIDO; Hiroshi; (Osaka, JP) ; HIRAMATU;
Akinori; (Nara, JP) ; HASEGAWA; Junichi;
(Osaka, JP) ; UEDA; Daisuke; (Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Panasonic Intellectual Property Management Co., Ltd. |
Osaka |
|
JP |
|
|
Family ID: |
53884091 |
Appl. No.: |
14/615739 |
Filed: |
February 6, 2015 |
Current U.S.
Class: |
315/295 |
Current CPC
Class: |
H05B 45/46 20200101;
H05B 45/44 20200101; Y02B 20/30 20130101; H05B 45/50 20200101; H05B
45/10 20200101; H05B 45/37 20200101; Y02B 20/346 20130101 |
International
Class: |
H05B 33/08 20060101
H05B033/08 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 7, 2014 |
JP |
2014-045605 |
Claims
1. A light source device, comprising: light sources; switches that
are connected with the light sources in series, respectively; and a
control unit that is configured to turn on and off the switches,
wherein each of the light sources comprises one or more solid light
emitting elements, and wherein the control unit is configured to,
after a DC voltage applied to the light sources exceeds a
prescribed threshold, turn on and off the switches in prescribed
order.
2. The light source device according to claim 1, wherein the
control unit is configured to output, to an outside, an information
set related to the characteristics of the light sources, by turning
on and off the switches in the prescribed order.
3. The light source device according to claim 2, wherein the
control unit is configured to output, to the outside, a number of
the light sources and a rated current value of each light source,
as the information set.
4. A lighting device, comprising a power supply and a controller,
the power supply being configured to be electrically connected with
the light source device according to claim 1, the power supply
being further configured to be capable of changing a DC output
voltage and a DC output current, the controller being configured to
control the power supply to adjust the DC output voltage and the DC
output current, the controller being further configured to, after
the DC output voltage applied to the light source device exceeds
the prescribed threshold, acquire the characteristics of the light
sources of the light source device based on a change in a voltage
level of the DC output voltage applied to the light source
device.
5. A lighting device, comprising a power supply and a controller,
the power supply being configured to be electrically connected with
the light source device according to claim 2, the power supply
being further configured to be capable of changing a DC output
voltage and a DC output current, the controller being configured to
control the power supply to adjust the DC output voltage and the DC
output current, the controller being further configured to, after
the DC output voltage applied to the light source device exceeds
the prescribed threshold, acquire the characteristics of the light
sources of the light source device based on a change in a voltage
level of the DC output voltage applied to the light source
device.
6. A lighting device, comprising a power supply and a controller,
the power supply being configured to be electrically connected with
the light source device according to claim 3, the power supply
being further configured to be capable of changing a DC output
voltage and a DC output current, the controller being configured to
control the power supply to adjust the DC output voltage and the DC
output current, the controller being further configured to, after
the DC output voltage applied to the light source device exceeds
the prescribed threshold, acquire the characteristics of the light
sources of the light source device based on a change in a voltage
level of the DC output voltage applied to the light source
device.
7. The lighting device according to claim 4, wherein the controller
is configured to, when determining that the characteristics of the
light sources is inappropriate, control the power supply to reduce
or stop the DC output voltage and the DC output current.
8. The lighting device according to claim 5, wherein the controller
is configured to, when determining that the characteristics of the
light sources is inappropriate, control the power supply to reduce
or stop the DC output voltage and the DC output current.
9. The lighting device according to claim 6, wherein the controller
is configured to, when determining that the characteristics of the
light sources is inappropriate, control the power supply to reduce
or stop the DC output voltage and the DC output current.
10. A luminaire, comprising the light source device according to
claim 1, a lighting device, and a luminaire body configured to
support at least the light source device, the lighting device
comprising a power supply and a controller, the power supply being
configured to be electrically connected with the light source
device, the power supply being further configured to be capable of
changing a DC output voltage and a DC output current, the
controller being configured to control the power supply to adjust
the DC output voltage and the DC output current, the controller
being further configured to, after the DC output voltage applied to
the light source device exceeds the prescribed threshold, acquire
the characteristics of the light sources of the light source device
based on a change in a voltage level of the DC output voltage
applied to the light source device.
11. A luminaire, comprising the light source device according to
claim 2, a lighting device, and a luminaire body configured to
support at least the light source device, the lighting device
comprising a power supply and a controller, the power supply being
configured to be electrically connected with the light source
device, the power supply being further configured to be capable of
changing a DC output voltage and a DC output current, the
controller being configured to control the power supply to adjust
the DC output voltage and the DC output current, the controller
being further configured to, after the DC output voltage applied to
the light source device exceeds the prescribed threshold, acquire
the characteristics of the light sources of the light source device
based on a change in a voltage level of the DC output voltage
applied to the light source device.
12. A luminaire, comprising the light source device according to
claim 3, a lighting device, and a luminaire body configured to
support at least the light source device, the lighting device
comprising a power supply and a controller, the power supply being
configured to be electrically connected with the light source
device, the power supply being further configured to be capable of
changing a DC output voltage and a DC output current, the
controller being configured to control the power supply to adjust
the DC output voltage and the DC output current, the controller
being further configured to, after the DC output voltage applied to
the light source device exceeds the prescribed threshold, acquire
the characteristics of the light sources of the light source device
based on a change in a voltage level of the DC output voltage
applied to the light source device.
13. The luminaire according to claim 10, wherein the controller is
configured to, when determining that the characteristics of the
light sources is inappropriate, control the power supply to reduce
or stop the DC output voltage and the DC output current.
14. The luminaire according to claim 11, wherein the controller is
configured to, when determining that the characteristics of the
light sources is inappropriate, control the power supply to reduce
or stop the DC output voltage and the DC output current.
15. The luminaire according to claim 12, wherein the controller is
configured to, when determining that the characteristics of the
light sources is inappropriate, control the power supply to reduce
or stop the DC output voltage and the DC output current.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The application is based upon and claims the benefit of
priority of Japanese Patent Application No. 2014-045605, filed on
Mar. 7, 2014, the entire contents of which are incorporated herein
by reference.
TECHNICAL FIELD
[0002] The disclosure relates generally to light source devices,
lighting devices, and luminaries, and more particularly, to a light
source device including a light source, a lighting device
configured to supply power to the light source device to light the
light source, and a luminaire using the light source device and the
lighting device.
BACKGROUND ART
[0003] Conventionally, there is a luminaire as described in JP
2005-93196 A (hereinafter, referred to as "document 1"). The
conventional example in the document 1 includes an illumination
head (a light source device) in which one or more light-emitting
elements are arbitrarily arranged, and a power supply device (a
lighting device) that is configured to supply power to the
illumination head.
[0004] Here, plural types of illumination heads are previously
provided, which have different rated current values, depending on a
difference between the numbers of light-emitting elements in the
plural types of illumination heads. Any one of the plural types of
illumination heads is selectively connected with the power supply
device. The plural types of illumination heads include
identification resistors. The respective identification resistors
have resistance values corresponding to the rated current values of
the plural types of the illumination heads.
[0005] The power supply device is configured to determine the type
(a rated current value) of an illumination head connected with an
output terminal of the power supply device by detecting a
resistance value of an identification resistor of the connected
illumination head, and adjust an output current according to the
determination result.
[0006] That is, in the conventional example of the document 1, it
is possible to light the light-emitting elements of each
illumination head at its rated current, using a single power supply
device, regardless of characteristics (the rated current values) of
the illumination heads.
[0007] However, in the conventional example of the document 1, it
is required to more enhance accuracy of detecting the resistance
value of the identification resistor with increase in the number of
the plural types of illumination heads (light source devices).
Also, when light emission colors or color temperatures are
different in addition to the rated current values as the
characteristics of the plural types of illumination heads, it is
hard to identify the type of the connected illumination head by
only the resistance value of the identification resistor.
SUMMARY
[0008] It is an object of the present technology to provide a light
source device, a lighting device and a luminaire, which can enhance
accuracy of identifying characteristics of a light source.
[0009] A light source device according to an aspect of the present
invention includes: light sources; switches that are connected with
the light sources in series, respectively; and a control unit that
is configured to turn on and off the switches. Each of the light
sources includes one or more solid light emitting elements. The
control unit is configured to, after a DC voltage applied to the
light sources exceeds a prescribed threshold, turn on and off the
switches in prescribed order.
[0010] A lighting device according to an aspect of the present
invention includes a power supply and a controller. The power
supply is configured to be electrically connected with the light
source device. The power supply is further configured to be capable
of changing a DC output voltage and a DC output current. The
controller is configured to control the power supply to adjust the
DC output voltage and the DC output current. The controller is
further configured to, after the DC output voltage applied to the
light source device exceeds the prescribed threshold, acquire the
characteristics of the light sources of the light source device
based on a change in a voltage level of the DC output voltage
applied to the light source device.
[0011] A luminaire according to an aspect of the present invention
includes the light source device, a lighting device, and a
luminaire body configured to support at least the light source
device. The lighting device includes a power supply and a
controller. The power supply is configured to be electrically
connected with the light source device. The power supply is further
configured to be capable of changing a DC output voltage and a DC
output current. The controller is configured to control the power
supply to adjust the DC output voltage and the DC output current.
The controller is further configured to, after the DC output
voltage applied to the light source device exceeds the prescribed
threshold, acquire the characteristics of the light sources of the
light source device based on a change in a voltage level of the DC
output voltage applied to the light source device.
[0012] The light source device, lighting device and luminaire
according to the present technology are configured to transmit
characteristics of a light source, based on a voltage change
depending on a pattern (regularity) of on and off of a switch.
Therefore, the light source device, lighting device and luminaire
according to the present technology can more enhance accuracy of
identifying the characteristics of the light source, compared with
the conventional example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The figures depict one or more implementations in accordance
with the present teaching, by way of example only, not by way of
limitations. In the figures, like reference numerals refer to the
same or similar elements.
[0014] FIG. 1 is a circuit configuration diagram illustrating a
light source device (a light source unit) and a lighting device (a
power supply unit) according to an embodiment;
[0015] FIG. 2 is a time chart for explaining operation of the light
source device and the lighting device in a steady-state according
to the embodiment;
[0016] FIG. 3 is a time chart for explaining operation of the light
source device and the lighting device, immediately after activation
time, according to the embodiment;
[0017] FIG. 4 is a time chart for explaining operation of the light
source device and the lighting device, immediately after activation
time, according to the embodiment;
[0018] FIG. 5 is a time chart for explaining operation of the light
source device and the lighting device, immediately after activation
time, according to the embodiment; and
[0019] FIG. 6 is a sectional view of a luminaire according to the
embodiment.
DETAILED DESCRIPTION
[0020] Hereinafter, a light source device, a lighting device and a
luminaire according to an embodiment will be described in detail
with reference to drawings.
[0021] As shown in FIG. 1, the light source device (a light source
unit 1) of the embodiment includes light sources 10 (10A, 10B and
10C; three in the illustrated example), and a circuit part. The
light source 10A includes: a series circuit (LED array 104A) of
light emitting diodes 100A, 101A, 102A and 103A (four in the
illustrated example) as solid light emitting elements; and a
resistor 105A that is connected in parallel with the LED array
104A. Also, the light source 10B includes: a series circuit (LED
array 104B) of light emitting diodes 100B, 101B, 102B and 103B as
solid light emitting elements; and a resistor 105B that is
connected in parallel with the LED array 104B. Similarly, the light
source 10C includes: a series circuit (LED array 104C) of light
emitting diodes 100C, 101C, 102C and 103C as solid light emitting
elements; and a resistor 105C that is connected in parallel with
the LED array 104C. Hereinafter, the three light sources 10 are
referred to as a first light source 10A, a second light source 10B
and a third light source 10C, respectively.
[0022] The above-mentioned circuit part includes a control unit 11,
a control power supply circuit 12, switches (switching elements)
13A, 13B and 13C, a resistor 14 and a voltage detection circuit 15.
The circuit part is electrically connected with the lighting device
(a power supply unit 2) via a first terminal 4 on a high potential
side of the circuit part and a second terminal 5 on a low potential
side of the circuit part.
[0023] The first terminal 4 is connected with a positive electrode
of each of the light sources 10A, 10B and 10C (that is, an anode of
each of the light emitting diodes 103A, 103B and 103C). The second
terminal 5 is connected with a negative electrode of each of the
light sources 10A, 10B and 10C (that is, a cathode of each of the
light emitting diodes 100A, 100B and 100C). The switches 13A to 13C
are configured by n-channel field-effect transistors. A source
terminal of each of the switches 13A to 13C is connected with the
second terminal 5. A drain terminal of the switch 13A (a first
switch) is connected with a negative electrode of the first light
source 10A. A gate terminal of the first switch 13A is connected
with the control unit 11. Also, a drain terminal of the switch 13B
(a second switch) is connected with a negative electrode of the
second light source 10B. A gate terminal of the second switch 13B
is connected with the control unit 11. Similarly, a drain terminal
of the switch 13C (a third switch) is connected with a negative
electrode of the third light source 10C. A gate terminal of the
third switch 13C is connected with the control unit 11. The control
unit 11 includes a Micro-Processing Unit (MPU), and gate terminals
of the switches 13A to 13C are connected with output ports of the
control unit 11, respectively. That is, the control unit 11 is
configured to execute programs stored in a built-in memory and
output a drive signal via a corresponding output port to turn on
each of the switches 13A to 13C, individually.
[0024] The control power supply circuit 12 includes, as a main
component, a constant voltage regulator IC, and is configured to
generate a prescribed constant voltage, as a power supply for
operating the control unit 11. The resistor 14 is disposed between
the second terminal 5 and a connecting point P1 at which the
negative electrodes of the light sources 10A to 10C are connected
with each other. The control unit 11 is configured to detect (a
magnitude of) an output current I2 of the power supply unit 2 based
on a voltage across the resistor 14.
[0025] The voltage detection circuit 15 includes a resistance
voltage-diving circuit that is connected in series between the
first and second terminals 4 and 5. That is, the voltage detection
circuit 15 is configured to output, to the control unit 11, a
detection voltage that is proportional to an input voltage (an
output voltage V2 of the power supply unit 2) applied between the
first and second terminals 4 and 5.
[0026] As shown in FIG. 1, the power supply unit 2 includes a
controller 20, a noise filter 21, a full-wave rectifier circuit 22,
a power factor improvement circuit 23, a DC converter circuit 24, a
voltage detection circuit 25 and a control power supply circuit 26,
and smoothing capacitors 27 and 28.
[0027] The noise filter 21 is configured to remove harmonic noise
in an AC voltage and an AC current supplied from an AC power source
3. The full-wave rectifier circuit 22 includes, for example, a
diode bridge to perform full-wave rectification of the AC voltage
and the AC current received via the noise filter 21.
[0028] The power factor improvement circuit 23 includes a
well-known boosting chopper circuit, and is configured to boost, to
a desired DC voltage V1, a pulsating voltage that is output from
the full-wave rectifier circuit 22, and output the DC voltage
V1.
[0029] The DC converter circuit 24 includes a well-known step-down
chopper circuit, and is configured to step down the DC voltage V1
that is output from the power factor improvement circuit 23 and
then smoothed by the smoothing capacitor 27. The smoothing
capacitor 28 is connected between output terminals of the DC
converter circuit 24. A DC voltage V2 (smaller than the DC voltage
V1) that is output from the DC converter circuit 24 and then
smoothed by the smoothing capacitor 28 is supplied to the light
source unit 1 via the first and second terminals 4 and 5.
Hereinafter, the DC voltage V2 is referred to as an "output
voltage" V2.
[0030] The first terminal 4 is connected with an output terminal on
a high potential side of the DC converter circuit 24 and an end on
a high potential side of the smoothing capacitor 28. The second
terminal 5 is connected with an output terminal on a low potential
side of the DC converter circuit 24 and an end on a low potential
side of the smoothing capacitor 28.
[0031] The controller 20 is configured to independently control the
power factor improvement circuit 23 and the DC converter circuit
24, individually. However, the controller 20 may include an
integrated circuit for controlling the power factor improvement
circuit 23, an integrated circuit for controlling the DC converter
circuit 24, and an integrated circuit for controlling those two
integrated circuits.
[0032] The voltage detection circuit 25 includes a resistance
voltage-diving circuit that is connected in parallel with the
smoothing capacitor 28. That is, the voltage detection circuit 25
is configured to output, to the controller 20, a detection voltage
that is proportional to a voltage (the output voltage V2 of the
power supply unit 2) across the smoothing capacitor 28.
[0033] The controller 20 is configured to apply a feedback control
to the power factor improvement circuit 23 so as to make the DC
voltage V1 agree with a prescribed target value. The controller 20
is further configured to apply a feedback control to the DC
converter circuit 24 so as to make the output voltage V2 agree with
a prescribed value. In addition, the controller 20 is configured to
intermittently operate the DC converter circuit 24 in response to a
light control level (a dimming level) indicated by a light control
signal (a dimming signal) to perform burst light control (burst
dimming control). Note that, the burst light control mentioned here
is a light control method of adjusting (controlling) light quantity
of each of the light sources 10A to 10C by periodically turning on
and off current flowing to the light sources 10A to 10C at a
prescribed burst period to change a ratio of an ON-period (a duty
ratio).
[0034] Next, operation of the light source unit 1 and power supply
unit 2, in a steady-state (stable lighting state), of the
embodiment will be described with reference to a time chart of FIG.
2. Here, the output current I2 in FIG. 2 denotes an output current
of the power supply unit 2 (see FIG. 1).
[0035] The controller 20 of the power supply unit 2 intermittently
operates the DC converter circuit 24 at a duty ratio (a ratio of an
operating period (ON period) to a burst period) depending on a
content indicated by the light control signal. The control unit 11
of the light source unit 1 turns on only the first switch 13A (at a
time t=t10), when detecting that the output current I2 is reduced
to a prescribed value or less in a pause period (OFF state) of the
DC converter circuit 24. Note that, in the pause period of the DC
converter circuit 24, electric charge stored in the smoothing
capacitor 28 before the pause period is discharged, and
accordingly, the output current I2 is kept to be supplied to the
light source unit 1.
[0036] The controller 20 starts operation of the DC converter
circuit 24 (at the time t=t11) after the pause period (OFF state).
When the output current I2 is output by the operation of the DC
converter circuit 24, a voltage across the smoothing capacitor 28
(the output voltage V2) is increased to a value (VA) of a forward
voltage across the first light source 10A connected in series with
the first switch 13A.
[0037] The controller 20 temporarily stops the operation of the DC
converter circuit 24 at a time point (the time t=t12) when an
operating period (a first operating period TA) corresponding to the
first light source 10A elapses after a time point (the time t=t11)
of starting the operation of the DC converter circuit 24, and
starts clocking of a pause period corresponding to the first light
source 10A.
[0038] The control unit 11 of the light source unit 1 turns on only
the second switch 13B (at the time t=t13), when detecting that the
output current I2 is reduced to a prescribed value or less in the
pause period corresponding to the first light source 10A.
[0039] The controller 20 starts the operation of the DC converter
circuit 24 (at the time t=t14) after the pause period corresponding
to the first light source 10A. When the output current I2 is output
by the operation of the DC converter circuit 24, the output voltage
V2 is increased to a value (VB) of a forward voltage across the
second light source 10B connected in series with the second switch
13B.
[0040] The controller 20 temporarily stops the operation of the DC
converter circuit 24 at a time point (the time t=t15) when an
operating period (a second operating period TB) corresponding to
the second light source 10B elapses after a time point (the time
t=t14) of starting the operation of the DC converter circuit 24,
and starts clocking of a pause period corresponding to the second
light source 10B.
[0041] The control unit 11 of the light source unit 1 turns on only
the third switch 13C (at the time t=t16), when detecting that the
output current I2 is reduced to a prescribed value or less in the
pause period corresponding to the second light source 10B.
[0042] The controller 20 starts the operation of the DC converter
circuit 24 (at the time t=t17) after the pause period corresponding
to the second light source 10B. When the output current I2 is
output by the operation of the DC converter circuit 24, the output
voltage V2 is increased to a value (VC) of a forward voltage across
the third light source 10C connected in series with the third
switch 13C.
[0043] The controller 20 temporarily stops the operation of the DC
converter circuit 24 at a time point (the time t=t18) when an
operating period (a third operating period TC) corresponding to the
third light source 10C elapses after a time point (the time t=t17)
of starting the operation of the DC converter circuit 24, and
starts clocking of a pause period corresponding to the third light
source 10C.
[0044] As described above, the control unit 11 is configured to
alternatively turn on the three switches 13A to 13C in prescribed
order at a prescribed cycle (hereinafter, referred to as a "switch
cycle"). Here, when the three switches 13A to 13C have light
emission colors different from each other, it is possible to adjust
(control) color and quantity of light (illumination light) to be
emitted to an illumination space from the light source unit 1,
according to a ratio of the respective operating periods TA, TB and
TC corresponding to the light sources 10A to 10C. The switch cycle
is preferably set to be in a range of 1/1000 sec to 1/120 sec so
that switching of the light sources 10A to 10C is less likely to be
perceived by people around. Note that, the control unit 11 is not
limited to a configuration of cyclically lighting the three light
sources 10A to 10C sequentially. The control unit 11 may be
configured to light only any one of the three light sources 10A to
10C, or alternatively light any two of the three light sources 10A
to 10C.
[0045] Next, characteristic operation (just after starting) of the
light source unit 1 and the power supply unit 2 of the embodiment
will be described with reference to a time chart of FIG. 3.
[0046] When the AC power source 3 starts power supply to the power
supply unit 2 at a time t=t0, the smoothing capacitor 27 is charged
up to a peak voltage of a power supply voltage (about 141 V in a
case where an effective value is 100 V). In addition, the control
power supply circuit 26 is activated and provides a control power
supply to the controller 20, and accordingly, the controller 20 is
also activated. The smoothing capacitor 28 is charged up to a
voltage value of Vk1 that is determined by impedance of the light
source unit 1 at the time t=t0.
[0047] When the output voltage V2 is increased and the control
power supply circuit 12 of the light source unit 1 becomes a state
capable of providing a control power supply, the control unit 11 is
activated (at the time t=t1). The control unit 11 starts, when its
operation becomes a stable state, a processing (program) of
transmitting identification information to the controller 20 of the
power supply unit 2. Note that, the controller 20 is configured to
perform constant current control, by a current value sufficiently
lower than a target value (output current I2) described later,
through the power factor improvement circuit 23 and the DC
converter circuit 24 before completion of the processing of
transmitting the identification information. The sufficiently low
current value mentioned here is preferably in a range that no light
source emits light, for example.
[0048] The control unit 11 first turns on only the first switch 13A
at the time t=t2. Due to an ON-state of the first switch 13A,
current flows through the resistor 105A of the first light source
10A, and accordingly, the impedance of the light source unit 1 is
reduced. As a result, the output voltage V2 of the power supply
unit 2 is also reduced from Vk1 to Vk2. The controller 20 detects
the output voltage V2 of the DC converter circuit 24 (voltage
across the smoothing capacitor 28) with the voltage detection
circuit 25, and stores, in a built-in memory, information that the
output voltage V2 has been reduced from Vk1 to Vk2.
[0049] The control unit 11 turns on the second switch 13B at the
time t=t3 while keeping the ON-state of the first switch 13A. Due
to an ON-state of the second switch 13B, current flows through the
resistor 105B of the second light source 10B in addition to the
resistor 105A of the first light source 10A, and accordingly, the
impedance of the light source unit 1 is further reduced. As a
result, the output voltage V2 of the power supply unit 2 is also
reduced from Vk2 to Vk3. The controller 20 stores, in the built-in
memory, information that the output voltage V2 has been reduced
from Vk2 to Vk3, detected by the voltage detection circuit 25.
[0050] The control unit 11 turns on the third switch 13C at the
time t=t4 while keeping the ON-states of the first and second
switches 13A and 13B. Due to an ON-state of the third switch 13C,
current flows through the resistor 105C of the third light source
10C in addition to the resistors 105A and 105B of the first and
second light sources 10A and 10B, and accordingly, the impedance of
the light source unit 1 is further reduced. As a result, the output
voltage V2 of the power supply unit 2 is also reduced from Vk3 to
Vk4. The controller 20 stores, in the built-in memory, information
that the output voltage V2 has been reduced from Vk3 to Vk4,
detected by the voltage detection circuit 25.
[0051] Then, the control unit 11 turns off all of the switches 13A
to 13C at the time t=t5 to complete the processing (program) of
transmitting the identification information. Due to OFF-states of
all of the switches 13A to 13C, no current flows through all of the
resistors 105A to 105C of the light sources 10A to 10C. As a
result, the impedance of the light source unit 1 is returned to a
value before the time t=t2, and accordingly, the output voltage V2
of the power supply unit 2 is also returned from Vk4 to Vk1.
[0052] When the output voltage V2 detected by the voltage detection
circuit 25 is returned to an initial value (Vk1), the controller 20
determines that the processing of transmitting the identification
information by the control unit 11 has been completed Then, the
controller 20 identifies characteristics of the light source unit 1
based on a detection result related to the output voltage V2 stored
in the built-in memory, namely, a pattern in which the output
voltage V2 changes from Vk1 to Vk4 via Vk2 and Vk3.
[0053] In other words, the controller 20 can acquire
characteristics that the light source unit 1 includes three light
sources 10A to 10C, based on the output voltage V2 changing from
the initial value (Vk1) in three stages (Vk2, Vk3 and Vk4).
Further, the controller 20 can acquire other characteristics, such
as a rated current value or a light emission color of each of the
light sources 10A to 10C, based on time periods during which
respective values (Vk2, Vk3 and Vk4) are maintained.
[0054] The controller 20 determines a cycle of intermittently
operating the DC converter circuit 24 (that is, the switch cycle
for the switches 13A to 13C), according to the number of light
sources (three in the embodiment). In addition, the controller 20
determines a target value (output current I2) for performing
constant current control of the DC converter circuit 24, according
to the rated current value or the light emission color of each of
the light sources 10A to 10C. After that, the controller 20
performs, at the determined target value, the constant current
control of the DC converter circuit 24. Note that, the controller
20 performs, at a current value sufficiently lower than the target
value, the constant current control of the DC converter circuit 24
until the target value is determined after starting.
[0055] Here, in a case where the light source unit 1 includes only
two light sources 10A and 10B, as shown in FIG. 4, it is preferred
that the control unit 11 is configured to turn on the first switch
13A and the second switch 13B in that order, and then turn off all
of the two switches at the same time. In this case, the controller
20 can acquire characteristics that the light source unit 1
includes two light sources 10A and 10B, based on the output voltage
V2 changing from the initial value (Vk1) in two stages (Vk2 and
Vk3). Note that, the number of light sources 10 of the light source
unit 1 may be one, or four or more. Similarly, the number of
switches may be one, or four or more. The resistors 105A to 105C
respectively connected in parallel with the LED arrays 104A to 104C
may have the same resistance values, or different resistance
values. If those resistors 105A to 105C have resistance values
different from each other, it is possible to more easily identify a
change in the output voltage V2.
[0056] Here, in order to attain reduction of manufacturing cost,
for example, it is preferred to use a substrate on which three
light sources 10A to 10C can be mounted, even when the light source
unit 1 includes only two light sources 10A and 10B. That is, one
type of substrate can be used in the cases of two types of light
source units 1. Alternatively, electrically connecting of the light
sources 10A to 10C and the circuit part may be achieved by a
connector.
[0057] As described above, the light source device (light source
unit 1) of the embodiment includes: light sources 10A to 10C;
switches 13A to 13C that are connected with the light sources 10A
to 10C in series, respectively; and a control unit 11 that is
configured to turn on and off the switches 13A to 13C. Each of the
light sources 10A to 10C includes one or more solid light emitting
elements ((10A: light emitting diodes 100A, 101A, 102A and 103A),
(10B: light emitting diodes 100B, 101B, 102B and 103B) and (10C:
light emitting diodes 100C, 101C, 102C and 103C)). The control unit
11 is configured to, after a DC voltage V2 applied to the light
sources 10A to 10C exceeds a prescribed threshold (Vk1), turn on
and off the switches 13A to 13C in prescribed order depending on
characteristics of the light sources 10A to 10C. Here, the
prescribed order depending on the characteristics of the light
sources 10A to 10C means order depending on characteristics
information (such as the number of light sources, rated current
values, light emission colors, or color temperatures) of the light
sources 10A to 10C to be transmitted. For example, when the
characteristics information to be transmitted includes the number
of light sources, it is preferred that, as shown in FIG. 3, the
switches 13A to 13C are successively turned on, and then all of the
switches 13A to 13C are simultaneously turned off. For example,
when the characteristics information to be transmitted includes, in
addition to the number of light sources, other information (such as
rated current values, light emission colors, or color
temperatures), it is preferred that, as shown in FIG. 5, the
switches 13A to 13C are successively turned on, and then at least
one of the switches 13A to 13C is turned off and then the remaining
switches are simultaneously turned off.
[0058] The lighting device (power supply unit 2) of the embodiment
includes a power supply (DC converter circuit 24) and a controller
20. The power supply (DC converter circuit 24) is configured to be
electrically connected with the light source device (light source
unit 1). The power supply (DC converter circuit 24) is further
configured to be capable of changing a DC output voltage V2 and a
DC output current I2. The controller 20 is configured to control
the power supply (DC converter circuit 24) to adjust the DC output
voltage V2 and the DC output current I2. The controller 20 is
further configured to, after the DC output voltage V2 applied to
the light source device (light source unit 1) exceeds the
prescribed threshold, acquire (know) the characteristics of the
light sources 10A to 10C of the light source device (light source
unit 1), based on a change in a voltage level of the DC output
voltage V2 applied to the light source device (light source unit
1).
[0059] The light source device (light source unit 1) and the
lighting device (power supply unit 2) of the embodiment as above
are configured to transmit characteristics of the light sources,
based on a voltage change depending on a pattern (regularity) of on
and off of the switches 13A to 13C. Therefore, it is possible to
more enhance accuracy of identifying characteristics of the light
sources 10A to 10C, compared with the conventional example.
[0060] In the light source device (light source unit 1) of the
embodiment, the control unit 11 is preferably configured to output,
to an outside, an information set related to the characteristics of
the light sources 10A to 10C, by turning on and off the switches
13A to 13C in the prescribed order. Note that, the control unit 11
is preferably configured to output, to the outside, the number of
the light sources 10A to 10C and a rated current value of each
light source, as the information set.
[0061] In a configuration of transmitting characteristics of a
light source obtained by a resistor as the conventional example, it
is hard to transmit various information accurately. On the other
hand, because the light source device (light source unit 1) of the
embodiment is configured as above, it is possible to transmit
various information (the information set) accurately.
[0062] Here, as shown in FIG. 5, the control unit 11 may be
configured to turn off only any one of the three switches (e.g.,
the first switch 13A) first (at the time t=t5), and then turn off
the two remaining switches 13B and 13C at the same time (at the
time t=t6). In this case, the controller 20 can acquire (know)
characteristics, such as color temperatures, of the light sources
10A to 10C, based on a pattern in which the output voltage V2
changes from the initial value (Vk1) in four stages (Vk2, Vk3, Vk4
and Vk3 in that order). Note that, the pattern in which the control
unit 11 turns on and off the switches 13A to 13C is not limited to
the above-mentioned two patterns.
[0063] In the example of FIG. 5, the controller 20 determines the
switch cycle and a target value of the output current I2 according
to characteristics of the light sources 10A to 10C, after the
output voltage V2 is returned to the initial value (Vk1) (at the
time t=t6). Then, the controller 20 controls the DC converter
circuit 24, based on the determined switch cycle and target value
of the output current I2 after the time t=t7. However, the
controller 20 is preferably configured to, when determining that
the characteristics of the light sources 10 transmitted from the
control unit 11 is inappropriate (for example, in a case where the
number of light sources 10 exceeds an upper limit), stop the
operation of the power factor improvement circuit 23 and the DC
converter circuit 24. Alternatively, the controller 20 may be
configured to, when determining that the characteristics of the
light sources 10 transmitted from the control unit 11 is
inappropriate, set, to a value lower than normal, the target value
for performing the constant current control of the DC converter
circuit 24 to reduce the output current I2.
[0064] In the lighting device (power supply unit 2) of the
embodiment, the controller 20 is preferably configured to, when
determining that the characteristics of the light sources 10 is
inappropriate, control the power supply (DC converter circuit 24)
to reduce or stop the DC output voltage V2 and the DC output
current I2.
[0065] Because the lighting device (power supply unit 2) of the
embodiment is configured as above, it is possible to prevent a
situation where the lighting device (power supply unit 2) is not
operated normally due to power supply to the inappropriate light
source device (light source unit 1).
[0066] FIG. 6 shows a luminaire 6 of the embodiment.
[0067] The luminaire 6 of the embodiment is a downlight to be
embedded in a ceiling member 100. The luminaire 6 includes the
light source unit 1, a luminaire body 60 that houses therein and
supports the light source unit 1, and the power supply unit 2 that
is installed on the reverse side (upper side) of the ceiling member
100.
[0068] The luminaire body 60 is formed of metal material, such as
aluminum die-cast material, into a cylinder shape with a bottom
face and an opened top face (a lower face in FIG. 6). The LED
arrays 104A to 104C are attached on an inner bottom surface of the
luminaire body 60. The opened lower face of the luminaire body 60
is covered with a disk-shaped cover 61. The cover 61 is made of
light transmissive material, such as glass or polycarbonate.
[0069] The power supply unit 2 is housed in a metal-made case that
is formed into a rectangular box shape. The light source unit 1 and
the power supply unit 2 are electrically connected with each other
via power cables 62A and 62B, and connectors 63A and 63B.
[0070] While the foregoing has described what are considered to be
the best mode and/or other examples, it is understood that various
modifications may be made therein and that the subject matter
disclosed herein may be implemented in various forms and examples,
and that they may be applied in numerous applications, only some of
which have been described herein. It is intended by the following
claims to claim any and all modifications and variations that fall
within the true scope of the present teachings.
* * * * *